DDT

DDT spraying as part of a the National Malaria Eradication Program in the United States.

Credits:Centers for Disease Control and Prevention

DDT (dichloro-diphenyl-trichloroethane) was the first synthetic insecticide to be developed. The organic chemical compound was originally prepared in 1873, but it was not until 1939 that Paul Muller - a research chemist working for the Geigy company in Switzerland - recognised its qualities as a powerful insecticide. Used extensively during the Second World War, DDT was heralded as a major weapon in the fight against insect-born diseases such as malaria. Growing DDT resistance in the targeted pests, combined with its deadly impact on other wildlife, led to a dramatic reduction in its use.

DDT kills by disrupting chemical processes within the nervous system. Its success in subduing malaria in parts of Asia and Europe during the Second World War led directly to the World Health Organization’s global malaria eradication campaign, which was launched in 1955, and of which widespread ground-spraying with DDT was an integral part. As a highly effective insect killer it was also taken up as a more general pesticide for agricultural use.

Concerns about the wider environmental impact of DDT began within years of its widespread use. Such concerns were first brought to the general public by Rachel Carson in her book Silent Spring. By highlighting how DDT was poisoning and killing species way beyond those targeted - including mammals and birds - her book was instrumental in the eventual banning of DDT in America. The book has also been credited with helping to launch the environmental movement in the West.

DDT is still in use today in many parts of the world in the fight against malaria, but unlike 50 years ago its use is localised and controlled.